Automatic sprinkler head for fire extinguishers



AUTOMATIC SPRINKLER HEAD FOR FIRE EXTINGUISHERS Filed Nov. 7, 1942 2 Sheets-Sheet 1 n Tram/f x Feb. 27, 1945. ENSHAW 2,370,243

AUTOMATIC SPRINKLER HEAD FOR FIRE EXTINGUISHERS Filed Nov. 7, 1942 2 Sheets-Sheet 2 Zn yen for r/xa/mr 4. #ms/mw 114 I y M e) Q fliiorney Patented Feb. 27, 1945 UNITED STATES PATENT OFFICE AUTOMATIC SPRINKLER HEAD FOR FIRE EXTINGUISHERS Thomas Anthony Henshaw, .Gatley, England Application November 7, 1942, Serial No. 464,858 In Great Britain September 17, 1941 Claims. (C1. 169'--39) This invention relates to the automatic sprinkler heads of fire-extinguishing installations, as

used for example in factories, commercial build-.

' begins to collapse, puts an increased load on the supporting means to accelerate its breakdown. One at least of the sealing members, will be yieldable or resilient so as to ensure that the thrust of the supporting member will press each of the sealing members firmly against its seat.

In the sprinkler heads hitherto adopted, when these are so arranged that the escaping fluid can contact with the yielding support, the cooling effect on the support tends to decelerate the col lapse of the support. The present invention, on the contrary, ensures that, as the inner sealing member opens, during the initial collapsing movement of the fusible or other temperature-operated supporting means, the sudden increased load on the supporting means, set up by the fluid coming into contact with the outer, larger, sealing member, acts hammer-wise on the supporting means to accelerate its collapse. Moreover, in the previously-known sprinkler heads, if, under normal temperature conditions, there should be a leak or drip at the seal, much damage might be done by the escaping fluid. With the present invention, however, if there is a leak or drip at the inner seal, the outer seal serves as a check, and gives a second protection against possible dam age by escaping fluid.

A sprinkler head according to this invention, may be further characterised in that the means for stressing the removable parts of the seals to ensure a tight joint may be operated independently of any clamping or securing means for the non-removable parts of the seals. For example, when one of the seals is a diaphragm, as the outer one usually will be, the means for stressing and deflecting the diaphragm, into close contact with its valve member, will be arranged independently of the usual screwed ring which clamps the diaphragm in position in the head,

and will usuallybe arrangedbelow the temperature-operated, closure-supporting means, say between such means and the usual distributor plate. By reason of this independence, the clamping of the diaphragm against the valve may be efiected positively without fear of overloading the closures, and the closures may then be loaded to the desired amount without afiecting the clamping pressure on the diaphragm.

Another improvement contemplated by this invention is that the space between the inner and outer closures may be filled with an anti-freezing liquid, thus making the nozzles less sus ceptible to frost, and also rendering the seals more resistant to leakage when the pipes are filled with compressed air. main body of the head, and its supply pipes,

could be embedded in the ceiling or other structure and thereby be insulated against frost, whereas the extremities of the head, exposed to the elements, would be protected by the nonfreezing liquid contained within it. When the only purpose of the liquid seal is to counteract the escape of-compressed air it need not be of a nonfreezing type.

In the accompanying drawings, representative examples of the invention are illustrated:

Fig. l is a vertical section through a sprinkler head having a double seal according to one form of the invention; and

Fig. 2 is a similar view showing another form of the invention;

Fig. 3 illustrates a modification alternative 'to one feature shown in Fig. 2, and described in detail below. i

Fig. 4 is an enlarged sectional view of one of the sealing elements shown in Fig. 1;

Fig. 5 is a similar sectional view of one of the sealing elements shown in Fig. 4 taken in a plane at right angles to the plane of Fig. 4.

Fig. 6 is a cross-sectional view through one of the sealing elements shown in Fig. 5 viewed from below.

Referring first to Fig. l, the sprinkler head comprises a body I of usual type, with exteriorly screw threaded hub 2 and interiorly screw threaded flange 3, and around the central orifice in the hub, at its lower end, there is formed a raised head or flange 4, providing a valve seat. A diaphragm 5 of non-corrosive resilient metal, with a softer sealing ring 6 secured to it at its center. is clamped in the body in the usual way, by a screwed ring Tentering the said flange 3. From the ring 1 extends downwardly the usual spider .or cage 8, whose lower end both provides an abutment for the thermo-collapsible member Q and carries a distributor plate Ill. The member 9 and plate l (i are of conventional form. A single valve element is provided, having a flat upper part to engage the said bead or flange I and formthe In such event, the

inner closure, and a lower part of larger diameter to engage the seating ring Ii of the diaphragm 5 and form the outer closure. These two parts of the valve element are so dimensioned in thickness that the diaphragm 5 is deflected slightly and placed under stress by the pressing of the valve element; on to the said bead or flange 4. The valve element itself comprises a. stainless steel outer shell or thimble I la, a soft metal pad I lb in the upper part of the thimble, and a brass or other rigid metal base part I Ic secured thereto, the under-face of which latter is slotted to receive the upper end of the three-part thermocollapsible supporting member 9. Such slot, and the inter-engaging part of the collapsible member 5 may be shaped so as to have only slight contact with each other. Thatpart of the valve element II on which the sealing ring 4 rests is made flat so as to ensure a good fit even if there is slight eccentricity between the valve and diaphragm.

In the lower part of the spider 8', at its centre there i'sa screw threaded plug I2 whoseupper end carries a pivot or fulcrum I3 for" the thermocollapsible member 9', so that by advancing or withdrawing the plug, the pressureon the supporting member, and therefore on the two closure members, may be increased or reduced as the case may be. A suitable lock nut I4 is provided on the plug II, which nut may serve also to clamp in position the distributor or plate III. It will be seen that the supporting member may be: stressed sufliciently to ensure an efiective seal between the yieldable valve element II (because of the soft metal pad) and the valve seat 4 without the diaphragm 5 ofiering any limit, since the diaphragm may also yield, whilst merely increasing its own sealing eflect by so doing.

Some of the parts, for example the main. body and the distributor plate, may be of a plastic moulding, and in such case the. valve seat may be a metal insert cast into such moulding.

Preferably, the outer seal 5 is of the diaphragm type and the inner seal I'I is a plain valve, and, by a further preference, a single valve element is adapted both to operate asthe plain valve of the inner seal and to co-operate with the diaphragm in the outer seal, such single element being so shaped as to have-its two sealing surfaces'effective regardless of any mutual eccentricity between the two seals.

The terms thermo-collapsible" and temperature-operated must be taken to include any of the known forms of valve-closing means which are released by' an increase in temperature, and whether operating by expansion, explosion, or mere fusing or otherwise.

The invention is applicable to installations which are always water-filled, as well as to those which are sometimes water-filled and sometimes air-filled and also to those which normally are always air-filled.

When, as in the example just described with reference to Fig. 1, the outer seal is a diaphragm, it will follow the valve as the valve begins to fall. and will thereby maintain a seal temporarily, to prevent escaping fluid counter-acting the temperature effect on the supporting means, whilst as soon as the fluid is released by the inner valve, its impact, or even built-up pressure, on the diaphragm will cause the diaphragm to overload the yielding support and hasten its collapse, whereupon the valve member falls away as in known practice.

Referring now to Fig. 2-, the head is shown inverted" and with a fluid seal which may be a mere sealing expedient to counteract the escape of compressed air, or may be an anti-freezing expedient, as above referred to, or both. In the drawing, the valve seating 4 is of greater height than in the example of Fig. 1, and the valve member I I has a depending flange I5 to surround that seating, In order that. the diaphragm 5 shall not be displaced. past its central position, where it might remain due to its internal stresses, the body I of the sprinkler head is provided with a number of webs or fins I6 at spaced points around the seating member 4, which webs or fins serve as limiting stops for the diaphragm. The space between the two seals is filled with a sealing and/or anti-freezing liquid I! which extends up between the seating 4 and the flange I5.

In the modification of Fig. 3, instead of the limiting stops being on the body I in the form of the webs I6, they are on the diaphragm itself, in the form of tongues or extensions I8 which though normally clear of the shoulder I9 on the body I-, would contact with that shoulder before the diaphragm could pass its central position. As also shown in Fig. 3', the valve member I I has two separate sealing f'aces'one being a disc 20 to rest on the valveseat 4, and the other being the ring H to engage the rolled edge 22 of the diaphragm 5 In all the figures, the diaphragm is so-mounted as to have a normal position which necessitates its deflection beforethe two seals may be effected.

When both closure members are plain valves, there may b a spring or other resilient member between them to allow of the necessary independence of sealing pressure, the spring or other member having only a slight compression. In any case, the valve which engages the diaphragm (when employed) may be separate from that which engages the rigid seat, and in such event resilient pressur means may be placed between them.

The valve elements I I may be formed otherwise than as described and of any suitable material, in accordance with. known practice.

A further advantage, of this invention is that when the inner valve is a plain valve and the outer valve is a diaphragm, the testing pressures used (which are much higher than the normal pressures) do not normally come on the diaphragm. Also, when the system employs a constant high pressure fluid in the pipes, this pressure is not normally on the diaphragm. For these reasons the diaphragm is not liable to strains.

What I claim is:

1. A sprinkler head comprising a body with means to secure it to a sprinkler installation said body having a central orifice enlarged at one end and with a peripherally-screwed flange, a raised bead around the central orifice, within the flange, to form a valve seat, a diaphragm secured against, the body by a ring. screwed into said flange, said diaphragm having a central orifice co-axial with the valve seat, a valve member shaped at one part to close the orifice in the diaphragm, and at another part to pass through that orifice and (when the diaphragm is deflected) to co-operate as. a valve on the said valve seat, thermo-collapsible supporting means to hold the valve member in. the closed position, a spider or cage carrying the said ring and a distributing plate the. said spider or cage being provided with a screw-threaded abutment for the thermocollapsible supporting means and a screw whereby the diaphragm may be deflected and the valve moved on to its seat.

2. A sprinkler head provided with inner and outer sealing members with a cavity between them, said sealing members being supported in the closure position by the same thermo-collapsible means, the inner sealing member being the smaller and tending to open under interior pressure and the outer member being the larger and tending to close under interior pressure and arranged so that escape of fluid past the inner memberon to the outer member as the supporting means begins to collapse puts an increased load on the supporting member to accelerate its breakdown, said inner sealing member being plain and non-resilient and the outer sealing member being in the form of a resilient dia phragm.

3. A sprinkler head provided with inner and the outer closure member which is in the form of a resilient diaphragm, and the two sealing surfaces of the valve element being so shaped as to be effective regardless of any slight eccentricity between the valve and diaphragm.

4. A sprinkler head comprising, a body with means to secure it to a sprinkler installation, said body having a central orifice enlarged at one end and with a peripherally-screw threaded flange around the enlarged end, a' raised bead around the central orifice within the flange to form a valve seat, a diaphragm secured against the body by a ring screwed into said flange and having a central orifice "co-axial with the valve seat, a valve member shaped at one part to close the orifice in the diaphragm and at another party to pass through said orifice and when the diaphragm is deflected to co-operate as a valve with the said valve seat, and thermo-collapsible supporting means to hold the valve member in a closed position.

5. A sprinkler head according to claim 4,

wherein the valve member comprises a non-corrosive relatively thin and yieldable outer skin to engage the said valve seat and diaphragm with a relatively soft metal pad in that portion of the outer skin which engages the valve seat whereby the skin may yield where engaging the said seat, and a non-resilientouter part to resist the thrust of the supporting means.

THOMAS ANTHONY HENSHAW. 

